Best type of Cummins

[greystroke]

I have a 53 block ISB275 with no major issues. The 98 original thermostat in my engine was sticking which I feel was a bad design so if you buy and old 53 make sure newer thermostat is install. The design of this thermostat could have contributed to block failure during overheat.

I love this engine. I added a VMSpc and fuel guage for the lift pump so I could monitor diagnostics.

If you consider one use a bright light on the drivers side of the DP and look for repairs/leaks under the Turbo and around the freeze plugs. If it hasn't cracked by now it probably will be safe to buy. The Cummins rep I called said about 5 percent of the 53 blocks were affected.

I bought used and have been on the road for 10 years with this engine.

[Fiesta48]

Originally Posted by tmw188

Man after reading all this why would I even want a Cummins?

Because these very rare incidences are known problems. Do you want a engine type and not know which ones to avoid? Cummins are still making excellent RV engines, most quit due to EPA regs. I get 8.8-9.0 mpg on 35k lbs. And clean exhaust.

[Bob_C]

This old 99 Ram 5.9 has 200,000 and still going strong.....have replaced the exhaust manifold, crank sensor, lift pump, and injection pump......all fairly easy to do by myself...good set of gauges and looking at them also helps these live...

[alpenlite29]

I looked for a long time to find a 2003 dodge cummins 5.9 24 valve engine. When I did my research I concluded this was rated to be one of the best years with no issues mechanical or electronics. 2003 to 2003 1/2 manufacturer date code. I was told the the lift pump would fail around 90,000 miles and I just shook my head. Mine failed at 89,878 miles....LOL $500 repair cost. I now have about 110,000 and it has really been like a TIMEX. I wish the Transmission was a bit tighter feeling...but it has pulled a 30 foot fifth wheel for about 80,000 going back and forth all over every hill in the USA... Good luck on your purchase. I currently have 110,000..all trailer miles. 2003 dodge 2WD 3500 4 door. 8 foot bed.

[CountryFit]

My 2000 ISC 350 is amazing. Aside bulletproof it gets great fuel economy. On my recent trip it startled me with an unrealistic mpg, at this moment I am still unable to know the answer (maybe some one here can tell me why).

Last week I drove from Pahrump NV back to SF bay area. Started at the RV park behind the Best Western hotel. On the way out, I stopped at Fastrip on Rte 372 to fill up diesel. Knowing diesel $2.93 was much cheaper than that in CA so I tipped off all the way to the rim. About a half day later I was on 58W outside of Bakersfield CA and saw diesel $3.25 at a travel plaza. That was cheap comparing with that in bay area at about $4. Again I filled it up to the rim. Total 20 gallons.

I pulled out my phone and checked how many miles I had driven since Fastrip in Pahrump. Google Maps said 270 mile route was the shortest and I knew that was the only route I had driven. So, 270 miles with 20 gallons, that was 13.5 mpg!

How come? That couldn't be true, but that was true! I couldn't think of any reasoning - not a down hill drive, no tail wind, load was fair (black and grey tanks were empty, fresh water tank had 1/4 left, fuel tank was full). The only thing possible was the Fastrip in Pahrump might have real D2, while other cases the fuel was biodiesel; and I drove about 50 mph on desert roads and 62 on highways. But still unconvincing...

[barmcd]

Originally Posted by CountryFit

My 2000 ISC 350 is amazing. Aside bulletproof it gets great fuel economy. On my recent trip it startled me with an unrealistic mpg, at this moment I am still unable to know the answer (maybe some one here can tell me why).

Last week I drove from Pahrump NV back to SF bay area. Started at the RV park behind the Best Western hotel. On the way out, I stopped at Fastrip on Rte 372 to fill up diesel. Knowing diesel $2.93 was much cheaper than that in CA so I tipped off all the way to the rim. About a half day later I was on 58W outside of Bakersfield CA and saw diesel $3.25 at a travel plaza. That was cheap comparing with that in bay area at about $4. Again I filled it up to the rim. Total 20 gallons.

I pulled out my phone and checked how many miles I had driven since Fastrip in Pahrump. Google Maps said 270 mile route was the shortest and I knew that was the only route I had driven. So, 270 miles with 20 gallons, that was 13.5 mpg!

How come? That couldn't be true, but that was true! I couldn't think of any reasoning - not a down hill drive, no tail wind, load was fair (black and grey tanks were empty, fresh water tank had 1/4 left, fuel tank was full). The only thing possible was the Fastrip in Pahrump might have real D2, while other cases the fuel was biodiesel; and I drove about 50 mph on desert roads and 62 on highways. But still unconvincing...

13 mpg is pretty unbelievable, but I've gotten some wildly varying fuel consumption on trips. We went to El Paso from central Texas which is about a 3000 ft climb over 600 miles with the wind blowing out of the NW the whole time. Driving 70-72 mph I got close to 5.5 mpg. Paying $3.40 per gallon for diesel, it cost almost $300 to make the trip. On the way back, driving about 65 down that same 3000 ft I got 9 mpg. Diesel in central Texas is $2.69 and it cost about $150 for the same 600 miles.

Our ISC has been a reliable workhorse for us.

[CountryFit]

Originally Posted by barmcd

13 mpg is pretty unbelievable, but I've gotten some wildly varying fuel consumption on trips. We went to El Paso from central Texas which is about a 3000 ft climb over 600 miles with the wind blowing out of the NW the whole time. Driving 70-72 mph I got close to 5.5 mpg. Paying $3.40 per gallon for diesel, it cost almost $300 to make the trip. On the way back, driving about 65 down that same 3000 ft I got 9 mpg. Diesel in central Texas is $2.69 and it cost about $150 for the same 600 miles.

Our ISC has been a reliable workhorse for us.

Thanks Dennis for chiming in. In the past, I have seen around 9 to 9.5 mpg on flat roads, this time it just blew my mind. I thought it over, there was another factor in the mix - at the beginning of the 3 months sitting in the park, I added startron fuel treatment to the tank full to prevent from clogging (it happened once after a winter sitting). Could that have contributed to the mpg? I'll test more, to add it even in warmer seasons, to see how it performs. Amazing!

[greystroke]

Originally Posted by barmcd

13 mpg is pretty unbelievable, but I've gotten some wildly varying fuel consumption on trips. We went to El Paso from central Texas which is about a 3000 ft climb over 600 miles with the wind blowing out of the NW the whole time. Driving 70-72 mph I got close to 5.5 mpg. Paying $3.40 per gallon for diesel, it cost almost $300 to make the trip. On the way back, driving about 65 down that same 3000 ft I got 9 mpg. Diesel in central Texas is $2.69 and it cost about $150 for the same 600 miles.

Our ISC has been a reliable workhorse for us.

Not so unbelievable. I routinely get 9-13 towing the Lexus. The Cummins readout on my VMSpc reads an avg of 10.5 for about 120000 miles. If I get below 9 I know something is wrong.

[barmcd]

Originally Posted by greystroke

Not so unbelievable. I routinely get 9-13 towing the Lexus. The Cummins readout on my VMSpc reads an avg of 10.5 for about 120000 miles. If I get below 9 I know something is wrong.

What speed do you drive? I'd love to average 9 mpg.

[barmcd]

Originally Posted by CountryFit

Thanks Dennis for chiming in. In the past, I have seen around 9 to 9.5 mpg on flat roads, this time it just blew my mind. I thought it over, there was another factor in the mix - at the beginning of the 3 months sitting in the park, I added startron fuel treatment to the tank full to prevent from clogging (it happened once after a winter sitting). Could that have contributed to the mpg? I'll test more, to add it even in warmer seasons, to see how it performs. Amazing!

I don't know about the Startron. I had to use that treatment when I bought my coach as it had a biological infestation. I killed it with Biobor JF, but had to use Startron to get rid of the residue. Now I use Biorbor JF all the time to keep it at bay. I didn't notice any difference in mileage.

[greystroke]

Originally Posted by barmcd

What speed do you drive? I'd love to average 9 mpg.

60-65 on four lane. Remember I have an older Cummins with a 6 speed MD3060. I keep engine and Tranny well maintained.